U.S. patent application number 15/051468 was filed with the patent office on 2016-08-25 for single vessel range navigation and positioning of an ocean bottom seismic node.
This patent application is currently assigned to Seabed Geosolutions B.V.. The applicant listed for this patent is Seabed Geosolutions B.V.. Invention is credited to Jean-Baptiste Danre, Arne Henning Rokkan.
Application Number | 20160245945 15/051468 |
Document ID | / |
Family ID | 55451524 |
Filed Date | 2016-08-25 |
United States Patent
Application |
20160245945 |
Kind Code |
A1 |
Rokkan; Arne Henning ; et
al. |
August 25, 2016 |
SINGLE VESSEL RANGE NAVIGATION AND POSITIONING OF AN OCEAN BOTTOM
SEISMIC NODE
Abstract
Apparatuses, systems, and methods for monitoring, positioning,
and/or guiding a plurality of seismic nodes on or near the seabed
by a plurality of acoustic pinging devices coupled to a deployment
line and at least one surface buoy. The acoustic pinging devices
are configured to emit a unique ID that may be detected by a
receiver or transceiver located on each of the surface buoys. The
acoustic pinging devices may be coupled to each node or only to a
portion of the plurality of nodes (such as every two, three, or
four nodes). The monitoring system may be configured to identify
the ID, position, depth, and height of each seismic node during
travel to the seabed and upon node touchdown with the seabed. A
guidance system may be configured to guide the deployment of the
deployment cable based upon node position data determined by the
monitoring system.
Inventors: |
Rokkan; Arne Henning;
(Olsvik, NO) ; Danre; Jean-Baptiste; (Bergen,
NO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Seabed Geosolutions B.V. |
Leidschendam |
|
NL |
|
|
Assignee: |
Seabed Geosolutions B.V.
Leidschendam
NL
|
Family ID: |
55451524 |
Appl. No.: |
15/051468 |
Filed: |
February 23, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62119887 |
Feb 24, 2015 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01V 1/3852 20130101;
B63B 2022/006 20130101; G01V 1/3835 20130101; G01S 5/18 20130101;
B63B 35/00 20130101; B63B 22/00 20130101; G01V 1/3808 20130101 |
International
Class: |
G01V 1/38 20060101
G01V001/38; B63B 35/00 20060101 B63B035/00; B63B 22/00 20060101
B63B022/00 |
Claims
1. A monitoring system for the deployment of seismic nodes on or
near the seabed, comprising a plurality of autonomous seismic nodes
coupled to a cable; a plurality of acoustic pingers coupled to the
cable, wherein each pinger is configured to emit a ping at a
predetermined interval; a surface vessel, configured to deploy the
plurality of seismic nodes in a body of water; and at least one
surface buoy coupled to the surface vessel by a first buoy
connecting line, wherein each surface buoy comprises an acoustic
receiver configured to detect the emitted pings from the plurality
of acoustic pingers.
2. The system of claim 1, wherein the buoy connecting line is
configured to provide power to the surface buoy and data transfer
between the surface buoy and the surface vessel.
3. The system of claim 1, further comprising a plurality of surface
buoys, wherein at least one of the plurality of surface buoys is
coupled to the surface vessel by a first buoy connecting line and
at least one of the plurality of surface buoys is coupled to the
surface vessel by a second buoy connecting line.
4. The system of claim 1, further comprising a plurality of surface
buoys coupled to the surface vessel, wherein at least one of the
plurality of surface buoys is positioned on one side of the
deployment cable and at least one of the plurality of surface buoys
is positioned on the other side of the deployment cable.
5. The system of claim 1, further comprising a plurality of surface
buoys coupled to the surface vessel, wherein the plurality of
surface buoys are configured to substantially remain in a
predetermined position with respect to the other surface buoys.
6. The system of claim 1, wherein each of the plurality of acoustic
pingers is associated with a unique ID.
7. The system of claim 6, wherein the unique ID is based upon a
plurality of N frequencies and a plurality of Y internal addresses,
wherein the number of unique IDs comprises N.times.Y unique
IDs.
8. The system of claim 1, wherein each of the plurality of acoustic
pingers is coupled to a separate one of the plurality of seismic
nodes.
9. The system of claim 1, wherein each of the plurality of acoustic
pingers is configured to emit a ping at a predetermined interval
for a period of time, wherein the predetermined interval is at
least 2 seconds and the period of time is at least 5 minutes.
10. The system of claim 1, wherein each of the plurality of
acoustic pingers is coupled to and synchronized with a clock.
11. The system of claim 1, wherein the at least one surface buoy is
an unmanned surface vessel.
12. The system of claim 1, wherein the at least one surface buoy is
a self-positioning buoy.
13. The system of claim 1, wherein the at least one surface buoy is
self-powered.
14. The system of claim 1, wherein the monitoring system is
configured to identify the ID, position, depth, and height of each
seismic node upon touchdown with the seabed.
15. The system of claim 1, wherein the monitoring system is
configured to monitor the touchdown position of the plurality of
seismic nodes on the seabed and communicate the touchdown position
of each of the plurality of seismic nodes with the surface vessel
at approximately the same time as touchdown.
16. The system of claim 1, further comprising a guidance system
configured to guide the deployment cable from the surface vessel
based upon node position data determined by the monitoring
system.
17. The system of claim 1, wherein the surface vessel comprises an
acoustic receiver configured to detect the emitted pings from the
plurality of acoustic pingers.
18. The system of claim 1, wherein each of the plurality of
acoustic pingers is configured to be remotely actuated by a surface
transceiver.
19. The system of claim 1, wherein each of the plurality of
acoustic pingers is configured to be actuated by contact with
water.
20. A monitoring system for the deployment of autonomous seismic
nodes on or near the seabed, comprising a plurality of autonomous
seismic nodes coupled to a deployment cable; an acoustic pinger
coupled to each of the plurality of seismic nodes, wherein each
pinger is configured to emit a ping with a unique ID; a surface
vessel, configured to deploy the plurality of autonomous seismic
nodes in a body of water; and one or more surface acoustic
receivers located on one or more surface buoys positioned behind
the surface vessel, each configured to detect at least one of the
emitted pings.
21. The system of claim 20, wherein data is transmitted between the
one or more surface buoys and the surface vessel through a wireless
link.
22. A method for monitoring the deployment of a plurality of
seismic nodes on or near the seabed, comprising deploying a
plurality of autonomous seismic nodes from a surface vessel,
wherein the nodes are coupled to a deployment cable, wherein each
node is coupled to an acoustic pinger configured to emit a ping
with a unique ID; providing one or more surface buoys coupled to
the surface vessel, wherein each surface buoy comprises an acoustic
receiver configured to detect the emitted pings; and monitoring the
deployment of the deployed seismic nodes by receiving the emitted
pings at the one or more surface buoys.
23. The method of claim 22, further comprising emitting pings from
each of the acoustic pingers for a predetermined time after
deployment of the autonomous seismic nodes from the surface
vessel.
24. The method of claim 22, further comprising requesting each of
the acoustic pingers to transmit a ping in response to a request
from a surface transceiver.
25. The method of claim 22, further comprising determining the node
position of one or more of the plurality of seismic nodes based on
the received pings.
26. The method of claim 22, further comprising positioning the
deployment cable from the surface vessel based on one or more of
the determined positions of the plurality of seismic nodes.
27. The method of claim 22, further comprising modifying the
deployment position of the cable from the surface vessel based on a
touchdown position of one or more of the plurality of seismic
nodes.
28. The method of claim 22, further comprising modifying the
deployment position of the deployment cable from the surface vessel
based on one or more predicted touchdown positions of the plurality
of seismic nodes.
29. The method of claim 22, further comprising modifying the
deployment position of the cable from the surface vessel based on a
difference between an actual touchdown position of a seismic node
and a predetermined seabed position of the seismic node.
Description
PRIORITY
[0001] This application claims priority to U.S. provisional patent
application No. 62/119,887, filed on Feb. 24, 2015, the entire
content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to seismology and more particularly
relates to the use of a single marine vessel for the monitoring of
an ocean bottom seismic node, including the monitoring,
positioning, and/or guiding of deployed autonomous seismic
nodes.
[0004] 2. Description of the Related Art
[0005] Marine seismic data acquisition and processing generates a
profile (image) of a geophysical structure under the seafloor.
Reflection seismology is a method of geophysical exploration to
determine the properties of the Earth's subsurface, which is
especially helpful in determining an accurate location of oil and
gas reservoirs or any targeted features. Marine reflection
seismology is based on using a controlled source of energy
(typically acoustic energy) that sends the energy through
subsurface geologic formations. The transmitted acoustic energy
propagates downwardly through the subsurface as acoustic waves,
also referred to as seismic waves or signals. By measuring the time
it takes for the reflections or refractions to come back to seismic
receivers (also known as seismic data recorders or nodes), it is
possible to evaluate the depth of features causing such
reflections. These features may be associated with subterranean
hydrocarbon deposits or other geological structures of
interest.
[0006] There are many methods to record the reflections from a
seismic wave off the geological structures present in the surface
beneath the seafloor. In one method, a marine vessel tows an array
of seismic data recorders provided on streamers. In another method,
a series of interconnected sensors are integrated with a cable that
is towed behind a marine vessel and placed onto the seabed, which
is commonly known as ocean bottom cables. In another method,
autonomous seismic data recorders are placed directly on the ocean
bottom by a variety of mechanisms, including by the use of one or
more of Autonomous Underwater Vehicles (AUVs), Remotely Operated
Vehicles (ROVs), by dropping or diving from a surface or subsurface
vessel, or by attaching autonomous nodes to a cable that is
deployed behind a marine vessel. The data recorders may be
discrete, autonomous units, with no direct connection to other
nodes or to the marine vessel, where data is stored and
recorded.
[0007] When an ocean bottom cable or autonomous nodes attached to a
cable are deployed in the sea, it is desirable to know the position
of the cable and the positions of the nodes during and after
deployment. One common way to identify some portions of the
deployed cable is to use acoustic positioning transponders that are
selectively placed at various portions of the cable. In general, a
transponder is a remote acoustic beacon that requires the use of
expensive Ultra Short Baseline (USBL) technology, which calculates
the range and bearing for each transponder. Subsea transponders may
transmit an acoustic signal to a marine vessel that calculates the
position of the transponders (thus indicating the position of the
cable) on the sea floor using USBL (or similar) technology.
However, many problems exist with the use of transponders. Because
transponders are expensive (as well as the necessary equipment and
technology associated with the transponders and calculation of data
received from transponders), they are used infrequently on segments
of the deployment cable, often at intervals of 100 meters or more.
In operation, cable is laid down not in perfect lines or patterns
on the seabed, and thus the exact location of entire sections of
cable (and the relevant nodes) are effectively unknown between the
transponders. Recording seismic signals from the seabed requires
proper positioning of the node and/or sensor and different
orientations and improper configurations inhibit the coupling of
the seismic sensor to the seabed, providing poor or inaccurate
data. Still further, the deployment and retrieval of transponders
requires additional equipment on the deployment vessel and
additional time for the handling of such transponders.
[0008] A need exists for an improved method and system for the
monitoring and/or guiding of cable deployed with nodes on the
seabed, and in particular one that eliminates all or substantially
all of the transponders typically used in such applications and
eliminates the use of a USBL system. A new system is needed that is
more cost effective, allows better positioning and accuracy of
deployed nodes, and allows for the real-time (or near real-time)
guidance of the deployed nodes.
SUMMARY OF THE INVENTION
[0009] Apparatuses, systems, and methods for monitoring,
positioning, and/or guiding a plurality of seismic nodes on or near
the seabed by a plurality of acoustic pinging devices coupled to a
deployment line and at least one surface buoy. In one embodiment,
the plurality of seismic nodes comprises a plurality of autonomous
seismic nodes coupled to a deployment cable, and in another
embodiment the plurality of seismic nodes comprises a plurality of
sensors coupled to an ocean bottom cable.
[0010] The acoustic pinging devices are configured to emit a unique
ID that may be detected by a receiver or transceiver located on
each of the surface buoys. In one embodiment, each of the plurality
of acoustic pingers is associated with a unique ID that is based
upon a plurality of N frequencies and a plurality of Y internal
addresses, wherein the number of unique IDs comprises N.times.Y
unique IDs. In one embodiment each of the plurality of acoustic
pingers is coupled to a separate one of the plurality of seismic
nodes. In other embodiments the acoustic pinging devices may be
coupled to a portion of the plurality of nodes (such as every two,
three, or four nodes). The acoustic pinging devices may be attached
to the deployment cable itself, coupled to the node via a tether,
or be integrated within the node.
[0011] Each of the plurality of acoustic pingers may be configured
to emit a ping at a predetermined interval for a period of time. In
one embodiment, the predetermined interval is at least 2 seconds
and the period of time is at least 5 minutes. Each of the plurality
of acoustic pingers may be configured to be remotely actuated by a
surface transceiver and/or respond to a request from a surface
transceiver. In one embodiment, each of the plurality of acoustic
pingers is coupled to and synchronized with a clock. In one
embodiment, the pinger may comprise a transducer coupled to an
electronics module or board. The pinger (or a portion thereof) may
be located within a pressurized node housing of the node, may be
located external to a pressurized node housing (such as being
coupled to or placed within a node bumper or fender or other
non-pressurized housing), may be a stand-alone unit coupled to the
node by a connecting tether/wire, or may be a stand-alone unit
attached to the same deployment line as the seismic nodes.
[0012] In one embodiment, the monitoring system is configured to
identify the ID, position, depth, and height of each seismic node
during travel to the seabed and upon touchdown with the seabed. The
monitoring system may be configured to monitor the touchdown
position of the plurality of seismic nodes on the seabed and
communicate the touchdown position of each of the plurality of
seismic nodes with the surface vessel at approximately the same
time as touchdown. In one embodiment, a guidance system is
configured to guide the deployment of the deployment cable based
upon node position data determined by the monitoring system. The
surface vessel may be configured to determine the position of each
seismic node based on the detected pings and modify the deployment
of the plurality of seismic nodes based on the detected pings.
[0013] In one embodiment, disclosed is a monitoring system for the
deployment of seismic nodes on or near the seabed, comprising a
plurality of seismic nodes coupled to a cable, a plurality of
acoustic pingers coupled to the cable, wherein each pinger is
configured to emit a ping at a predetermined interval, a surface
vessel, configured to deploy the plurality of seismic nodes in a
body of water, and at least one surface buoy coupled to the surface
vessel by a first buoy connecting line, wherein each surface buoy
comprises an acoustic receiver configured to detect the emitted
pings. The buoy connecting line may be configured to provide power
to the surface buoy and data transfer between the surface buoy and
the surface vessel. In other embodiments, data is transmitted
between the at least one surface buoy to the surface vessel through
a wireless link.
[0014] In one embodiment, the system comprises a plurality of
surface buoys coupled to the surface vessel. In such an embodiment,
one of the plurality of surface buoys may be coupled to the surface
vessel by a first buoy connecting line and at one of the plurality
of surface buoys may be coupled to the surface vessel by a second
buoy connecting line. In other embodiments, at least one of the
plurality of surface buoys is positioned on one side of the
deployment cable and at least one of the plurality of surface buoys
is positioned on the other side of the deployment cable. The
plurality of surface buoys may be configured to substantially
remain in a predetermined position with respect to the other
surface buoys and/or with respect to the plurality of pingers
during the deployment of the seismic nodes. In some embodiments, a
surface buoy may be self-powered and/or self-positioning, and may
be an unmanned surface vessel (USV) or tail buoy. The surface buoy
may comprise a propulsion system. The surface buoy may also
comprise a GPS system, an acoustic transducer, and an acoustic
transceiver.
[0015] In another embodiment, disclosed is a monitoring system for
the deployment of autonomous seismic nodes on or near the seabed,
comprising a plurality of autonomous seismic nodes coupled to a
deployment cable, an acoustic pinger coupled to each of the
plurality of seismic nodes, wherein each pinger is configured to
emit a ping with a unique ID, a surface vessel, configured to
deploy the plurality of autonomous seismic nodes in a body of
water, and a plurality of surface acoustic receivers located behind
the surface vessel, each configured to detect at least one of the
emitted pings. In such an embodiment each of the plurality of
acoustic receivers may located on at least one surface buoy or a
USV. The surface buoys may be coupled to the surface vessel via a
connecting line or be self-powered and self-positioning and
connected to the surface vessel through a wireless link.
[0016] In another embodiment, disclosed is a method for monitoring
the deployment of a plurality of seismic nodes on or near the
seabed, comprising deploying a plurality of autonomous seismic
nodes from a surface vessel, wherein the nodes are coupled to a
deployment cable, wherein each node comprises an acoustic pinger
configured to emit a ping, providing a plurality of surface buoys
coupled to the surface vessel, wherein each surface buoy comprises
an acoustic receiver configured to detect the emitted pings, and
monitoring the deployment of the deployed seismic nodes by
receiving the emitted pings at the plurality of surface buoys.
[0017] The method may include emitting pings from each of the
acoustic pingers for a predetermined time after deployment. The
method may include requesting each of the acoustic pingers to
transmit a ping in response to a request from a surface
transceiver. The method may include determining the node position
of one or more of the plurality of seismic nodes at one or more
subsea positions based on the received pings and communicating to
the surface vessel such node position. In one embodiment, the node
position comprises position coordinates, depth, and height of the
node. The method may include positioning the deployment cable from
the surface vessel based on one or more determined of the plurality
of seismic nodes. The method may include monitoring a touchdown
position of each of the plurality of seismic nodes. In such an
embodiment, the method may include modifying the deployment
position of the cable from the surface vessel based on a touchdown
position of one or more of the plurality of seismic nodes and/or
one or more predicted touchdown positions of the plurality of
seismic nodes. The method may also include modifying the deployment
position of the cable from the surface vessel based on a difference
between an actual touchdown position of a seismic node and a
predetermined seabed position of the seismic node.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The following drawings form part of the present
specification and are included to further demonstrate certain
aspects of the present invention. The invention may be better
understood by reference to one or more of these drawings in
combination with the detailed description of specific embodiments
presented herein.
[0019] FIG. 1A is a schematic diagram illustrating one embodiment
of a system for marine deployment of an autonomous seismic
node.
[0020] FIG. 1B is a schematic diagram illustrating one embodiment
of a system for marine deployment of an autonomous seismic
node.
[0021] FIG. 2A illustrates a perspective view diagram of one
embodiment of an autonomous seismic node.
[0022] FIG. 2B illustrates a perspective view diagram of another
embodiment of an autonomous seismic node.
[0023] FIG. 3A illustrates one embodiment of an ocean bottom node
with a pinger within the pressurized node body.
[0024] FIG. 3B illustrates one embodiment of an ocean bottom node
with a pinger within the non-pressurized node body.
[0025] FIG. 3C illustrates one embodiment of an ocean bottom node
with a pinger coupled to the node body.
[0026] FIG. 3D illustrates one embodiment of an ocean bottom node
attached to a deployment line with a pinger coupled to the
deployment line.
[0027] FIG. 4 illustrates one embodiment of a node monitoring
system using a plurality of surface buoys.
[0028] FIG. 5 illustrates another embodiment of a node monitoring
system using a plurality of surface buoys.
[0029] FIG. 6 illustrates another embodiment of a node monitoring
system using a plurality of surface buoys.
[0030] FIG. 7 illustrates another embodiment of a node monitoring
system using a plurality of surface buoys.
[0031] FIG. 8 illustrates another embodiment of a node monitoring
system using a plurality of surface buoys.
[0032] FIG. 9 illustrates one method of using a plurality of
surface buoys to monitor node deployment.
DETAILED DESCRIPTION
[0033] Various features and advantageous details are explained more
fully with reference to the nonlimiting embodiments that are
illustrated in the accompanying drawings and detailed in the
following description. Descriptions of well known starting
materials, processing techniques, components, and equipment are
omitted so as not to unnecessarily obscure the invention in detail.
It should be understood, however, that the detailed description and
the specific examples, while indicating embodiments of the
invention, are given by way of illustration only, and not by way of
limitation. Various substitutions, modifications, additions, and/or
rearrangements within the spirit and/or scope of the underlying
inventive concept will become apparent to those skilled in the art
from this disclosure. The following detailed description does not
limit the invention.
[0034] Reference throughout the specification to "one embodiment"
or "an embodiment" means that a particular feature, structure, or
characteristic described in connection with an embodiment is
included in at least one embodiment of the subject matter
disclosed. Thus, the appearance of the phrases "in one embodiment"
or "in an embodiment" in various places throughout the
specification is not necessarily referring to the same embodiment.
Further, the particular features, structures, or characteristics
may be combined in any suitable manner in one or more
embodiments.
Node Deployment
[0035] FIGS. 1A and 1B illustrate a layout of a seabed seismic
recorder system that may be used with autonomous seismic nodes for
marine deployment. FIG. 1A is a diagram illustrating one embodiment
of a marine deployment system 100 for marine deployment of seismic
nodes 110. One or more marine vessels deploy and recover a cable
(or rope) with attached sensor nodes according to a particular
survey pattern. In an embodiment, the system includes a marine
vessel 106 designed to float on a surface 102 of a body of water,
which may be a river, lake, ocean, or any other body of water. The
marine vessel 106 may deploy the seismic nodes 110 in the body of
water or on the floor 104 of the body of water, such as a seabed.
In an embodiment, the marine vessel 106 may include one or more
deployment lines 108 (i.e., deployment cables). One or more seismic
nodes 110 may be attached directly to the deployment line 108.
Additionally, the marine deployment system 100 may include one or
more acoustic positioning transponders 112, one or more weights
114, one or more pop up buoys 116, and one or more surface buoys
118. As is standard in the art, weights 114 can be used at various
positions of the cable to facilitate the lowering and positioning
of the cable, and surface buoys 118 or pop up buoys 116 may be used
on the cable to locate, retrieve, and/or raise various portions of
the cable. Acoustic positioning transponders 112 may also be used
selectively on various portions of the cable to determine the
positions of the cable/sensors during deployment and post
deployment. The acoustic positioning transponders 112 may transmit
on request an acoustic signal to the marine vessel for indicating
the positioning of seismic nodes 110 on sea floor 104. In an
embodiment, weights 114 may be coupled to deployment line 108 and
be arranged to keep seismic nodes 110 in a specific position
relative to sea floor 104 at various points, such as during start,
stop, and snaking of deployment line 108.
[0036] FIG. 1B is a close-up view illustrating one embodiment of a
system 100 for marine deployment of seismic nodes 110. In an
embodiment, deployment line 108 may be a metal cable (steel,
galvanized steel, or stainless steel). Alternatively, deployment
line 108 may include chain linkage, rope (polymer), wire, or any
other suitable material for tethering to marine vessel 106 and
deploying one or more seismic nodes 110. In an embodiment,
deployment line 108 and seismic nodes 110 may be stored on marine
vessel 106. For example, the deployment line may be stored on a
spool or reel or winch. Seismic nodes 110 may be stored in one or
more storage containers. One of ordinary skill may recognize
alternative methods for storing and deploying deployment line 108
and seismic nodes 110.
[0037] In one embodiment, deployment line 108 and seismic nodes 110
are stored on marine vessel 106 and deployed from a back deck of
vessel 106, although other deployment locations from the vessel can
be used. As is well known in the art, deployment line 108, such as
a rope or cable, with a weight attached to its free end is dropped
from the back deck of the vessel. Seismic nodes 110 are preferably
directly attached in-line to deployment line 108 at a regular,
variable, or selectable interval (such as 25 meters) while
deployment line 108 is lowered through the water column and draped
linearly or at varied spacing onto the seabed. During recovery each
seismic node 110 may be clipped off deployment line 108 as it
reaches deck level of vessel 106. Preferably, nodes 110 are
attached directly onto deployment line 108 in an automated process
using node attachment or coupling machines on board the deck of the
marine vessel 106 at one or more workstations or containers.
Likewise, a node detaching or decoupling machine is configured to
detach or otherwise disengage seismic nodes 110 from deployment
line 108. Alternatively, seismic nodes 110 can be attached via
manual or semi-automatic methods. Seismic nodes 110 can be attached
to deployment line 108 in a variety of configurations, which allows
for free rotation with self-righting capability of seismic node 110
about deployment line 108 and allows for minimal axial movement on
deployment line 108 (relative to the acoustic wave length). For
example, deployment line 108 can be attached to the top, side, or
center of seismic node 110 via a variety of configurations.
[0038] Once deployment line 108 and seismic nodes 110 are deployed
on sea floor 104, a seismic survey can be performed. One or more
marine vessels 106 may contain a seismic energy source (not shown)
and transmit acoustic signals to sea floor 104 for data acquisition
by seismic nodes 110. Embodiments of system 100 may be deployed in
both coastal and offshore waters in various depths of water. For
example, the system may be deployed in a few meters of water or up
to several thousand meters of water. In some configurations surface
buoy 118 or pop up buoy 116 may be retrieved by marine vessel 106
when seismic nodes 110 are to be retrieved from seabed 104. Thus,
system 110 may not require retrieval by means of a submersible or
diver. Rather, pop up buoy 116 or surface buoy 118 may be picked up
on water surface 102 and deployment line 108 may be retrieved along
with seismic nodes 110.
[0039] As mentioned above, to perform a seismic survey that
utilizes autonomous seismic nodes, those nodes must be deployed and
retrieved from a vessel, typically a surface vessel. In one
embodiment a node storage and service system is coupled to one or
more deployment systems. The node storage and service system is
configured to handle, store, and service the nodes before and after
the deployment and retrieval operations performed by a node
deployment system. Such a node storage and service system is
described in more detail in U.S. Patent Publication No.
2015/0331130, filed on May 13, 2015, incorporated herein by
reference. Such a node deployment system is described in more
detail in U.S. Patent Publication No. 2016/0041283, filed on Aug.
6, 2015, entitled Overboard System for Deployment and Retrieval of
Autonomous Seismic Nodes, incorporated herein by reference.
Autonomous Seismic Node Design
[0040] FIG. 2A illustrates a perspective view diagram of autonomous
ocean bottom seismic node 110. Seismic node 110 may include body
202, such as a housing, frame, skeleton, or shell, which may be
easily dissembled into various components. Additionally, seismic
node 110 may include one or more power sources 204. Additionally,
the seismic node may include pressure release valve 216 configured
to release unwanted pressure from seismic node 110 at a pre-set
level. The valve protects against fault conditions like water
intrusion and outgassing from a battery package. Additionally, the
seismic node may include electrical connector 214 configured to
allow external access to information stored by internal electrical
components, data communication, and/or power transfer. During the
deployment the connector is covered by pressure proof watertight
cap 218 (shown in FIG. 2B). In other embodiments, the node does not
have an external connector and data is transferred to and from the
node wirelessly, such as via wireless electromagnetic or optical
links. In other embodiments, there may be multiple connectors on
the node, one for data transfer and one connector for power
transfer.
[0041] In an embodiment, the internal electrical components may
include one or more hydrophones 210, one or more (preferably three)
geophones 206 or accelerometers, and data recorder 212. In an
embodiment, data recorder 212 may be a digital autonomous recorder
configured to store digital data generated by the sensors or data
receivers, such as hydrophone 210 and the one or more geophones or
accelerometers 206. One of ordinary skill will recognize that more
or fewer components may be included in seismic node 110. For
example, there are a variety of sensors that can be incorporated
into the node including and not exclusively, inclinometers,
rotation sensors, translation sensors, heading sensors, and
magnetometers. Except for the hydrophone, these components are
preferably contained within the node housing that is resistant to
temperatures and pressures at the bottom of the ocean, as is well
known in the art. In an embodiment, the seismic node includes one
or more components configured for wireless transmission of data to
and from the node via electromagnetic or optical components. Data
can be retrieved from the node during deployment or, more
preferably, from the node while the node is on board the marine
vessel.
[0042] In an embodiment, power source 204 may be lithium-ion
battery cells or rechargeable battery packs for an extended
endurance (such as 90 days) on the seabed, but one of ordinary
skill will recognize that a variety of alternative battery cell
types or configurations may also be used. In one embodiment, the
power source for each node is one or more sets of rechargeable
batteries that can operate in a sealed environment, such as
lithium, nickel, lead, and zinc based rechargeable batteries.
Numerous rechargeable battery chemistries and types with varying
energy densities may be used, such as lithium ion, lithium ion
polymer, lithium ion iron phosphate, nickel metal hydride, nickel
cadmium, gel lead acid, and zinc based batteries. Various
rechargeable battery chemistries offer different operating
parameters for safety, voltage, energy density, weight, and size.
For example, voltage for a lithium ion battery may offer 3.6V with
an energy density of 240 Wh/kg and 550 Wh/L. In various
embodiments, the battery cell(s) may include a lithium-ion battery
cell or a plurality of lithium-ion windings. In another embodiment,
the battery cell may include a lithium-ion electrode stack. The
shape and size of the battery cell(s) may be configured according
to the power, weight, and size requirements of the seismic sensor
node. One of ordinary skill will recognize a variety of battery
cell types and configurations that may be suitable for use with the
present embodiments. In some embodiments, the rechargeable battery
pack includes a plurality of battery cells.
[0043] While the node in FIG. 2A is circular in shape, the node can
be any variety of geometric configurations, including square,
rectangular, hexagonal, octagonal, cylindrical, and spherical,
among other designs, and may or may not be symmetrical about its
central axis. In one embodiment, the node consists of a watertight,
sealed case or pressure housing that contains all of the node's
internal components. In another embodiment, the pressurizing node
housing is partially and/or substantially surrounded by a
non-pressurized node housing that provides the exterior shape,
dimensions, and boundaries of the node. In one embodiment, the node
is square or substantially square shaped so as to be substantially
a quadrilateral, as shown in FIG. 2B. One of skill in the art will
recognize that such a node is not a two-dimensional object, but
includes a height, and in one embodiment may be considered a box,
cube, elongated cube, or cuboid. While the node may be
geometrically symmetrical about its central axis, symmetry is not a
requirement. Further, the individual components of the node may not
be symmetrical, but the combination of the various components (such
as the pressurized housing and the non-pressurized housing) provide
an overall mass and buoyancy symmetry to the node. In one
embodiment, the node is approximately 350 mm.times.350 mm wide/deep
with a height of approximately 150 mm. In one embodiment, body 202
of the node has a height of approximately 100 mm and other coupling
features, such as node locks 220 or protrusions 242, may provide an
additional 20-50 mm or more height to the node.
[0044] In another embodiment, as shown in FIG. 2B, the node's
pressure housing may be coupled to and/or substantially surrounded
by an external non-pressurized node housing 240. Various portions
of non-pressurized node housing 240 may be open and expose the
pressurized node housing as needed, such as for hydrophone 210,
node locks 220, and data/power transfer connection 214 (shown with
a fitted pressure cap 218 in FIG. 2B). In one embodiment, the upper
and lower portions of the housing include a plurality of gripping
teeth or protrusions 242 for engaging the seabed and for general
storage and handling needs. Non-pressurized node housing 240
provides many functions, such as protecting the node from shocks
and rough treatment, coupling the node to the seabed for better
readings (such as low distortion and/or high fidelity readings) and
stability on the seabed, and assisting in the stackability,
storing, alignment, and handling of the nodes. Each node housing
may be made of a durable material such as rubber, plastic, carbon
fiber, or metal, and in one embodiment may be made of polyurethane
or polyethylene. In still other embodiments, seismic node 110 may
include a protective shell or bumper configured to protect the
body.
[0045] In one embodiment, seismic node 110 comprises one or more
direct attachment mechanisms and/or node locks 220 that may be
configured to directly attach seismic node 110 to a deployment line
108. This may be referred to as direct or in-line node coupling. In
one embodiment, the attachment mechanism 220 comprises a locking
mechanism to help secure or retain the deployment line 108 to the
seismic node 110. A plurality of direct attachment mechanisms may
be located on any surfaces of the node 110 or node housing 240. In
one embodiment, a plurality of node locks 220 is positioned
substantially in the center and/or middle of a surface of a node or
node housing. The node locks may attach directly to the pressure
housing and extend through the node housing 240. In this
embodiment, a deployment line, when coupled to the plurality of
node locks, is substantially coupled to the seismic node on its
center axis. In some embodiments, the node locks may be offset or
partially offset from the center axis of the node, which may aid
the self-righting, balance, and/or handling of the node during
deployment and retrieval. The node locks 220 are configured to
attach, couple, and/or engage a portion of the deployment line to
the node. Thus, a plurality of node locks 220 operates to couple a
plurality of portions of the deployment line to the node. The node
locks are configured to keep the deployment line fastened to the
node during a seismic survey, such as during deployment from a
vessel until the node reaches the seabed, during recording of
seismic data while on the seabed, and during retrieval of the node
from the seabed to a recovery vessel. The disclosed attachment
mechanism 220 may be moved from an open and/or unlocked position to
a closed and/or locked position via autonomous, semi-autonomous, or
manual methods. In one embodiment, the components of node lock 220
are made of titanium, stainless steel, aluminum, marine bronze,
and/or other substantially inert and non-corrosive materials,
including polymer parts. In some embodiments, a ferrule or other
stop 209 may be positioned on either side of the node to help
retain the node in a substantially constant position on the
deployment line and/or to help attach/detach the node to the
deployment line.
[0046] In one embodiment, each autonomous seismic node is coupled
to an acoustic pinging device. In other embodiments, rather than
having each node coupled to an acoustic pinging device, for cost
effectiveness and less system complexity, only some subset of the
total plurality of nodes is coupled to pingers. In such a system
the total number of nodes would be greater than the total number of
acoustic pinging devices. For example, in one embodiment, a pinger
is coupled to the deployment line every two, three, or four or more
nodes. Acoustic pinging devices are commercially available and, in
general, continuously transmit a sonar signal that can be detected
by an acoustic receiver. Each pinging device has a unique ID. In
one embodiment, each node has a unique pinger transmit frequency
such that a separate acoustic receiver can differentiate the pings
and, consequently, the nodes. In one embodiment, the acoustic
pinging device comprises a multi-frequency pinger which allows an
operator to select the desired transmit frequency in the field.
However, due to the limited number of frequencies that may be used
effectively in any communications system, in another embodiment
unique internal addresses can be provided to each
pinger/transducer. For example, if the communications system uses N
frequencies and Y addresses, then the set of pingers will have a
combination of N.times.Y unique IDs. This combination of different
internal addresses and frequencies allows for a unique
identification of a large number of acoustic devices/pingers.
Moreover, if the body of the acoustic device is equipped with a
radio frequency identification (RFID) device/chip, the
above-described internal address may be the RFID address. In one
embodiment, the internal addresses are short because they are sent
in the acoustic message by the pinger. In one embodiment, the
frequency range may be between 20-70 kHz, but other ranges are
possible. In still another embodiment, each pinger may be
configured to communicate and/or respond via a specific time slot,
such as the use of Time Division Multiple Access (TDMA). The use of
specific time-slots provides another mechanism to uniquely identify
the pingers.
[0047] FIGS. 3A-3D show various positions of an acoustic pinging
device in relation to a seismic node, which may include pressurized
node housing 303 surrounded by non-pressurized housing 301 (which
may be similar to FIG. 2B). Other internal components of the node
are not shown for convenience. All, substantially all, or a portion
thereof of pinger 311 may be located within pressurized node
housing 303 as shown in FIG. 3A, may be external to pressurized
node housing 303 (such as being coupled to or placed within a node
bumper or fender or other non-pressurized housing 301 as shown in
FIG. 3B), may be a stand-alone unit coupled to the node by
connecting tether/wire 313 as shown in FIG. 3C, or may be a
stand-alone unit attached to the same deployment line 108 as the
seismic nodes as shown in FIG. 3D.
[0048] In one embodiment, pinger 311 may comprise a transducer
(e.g., a vibrating ceramic element that may be configured to
generate and/or receive an acoustic wave) coupled to an electronics
module or board. In some embodiments, both the transducer and
electronics board are contained within the same protective
housing/body, and in other embodiments the electronics component of
the pinger is contained in a separate housing. Because the
transducer typically must be in contact with water, at least a
portion of the pinger (e.g., the transducer component) should be
exposed to the water. In one embodiment, pinger 311 is coupled to
power source 204 of the node, but in other embodiments pinger is
coupled to its own dedicated power source. The pinger is either
configured to emit a ping at a determined interval for a period of
time or respond and/or answer to one or more pinging requests from
a surface transceiver. In one embodiment, the pinger emits an
acoustic ping or signal every 2-10 seconds for a period of 5-20
minutes from the time of initial deployment from a vessel. The
pinger may be configured to change the duration of pings based on
the intended water deployment depth. Likewise, the interval of
pings can be varied based upon the depth and intended data analysis
requirements. In another embodiment, the pinger is interrogated by
a master transceiver and responds by an acoustic message depending
on its frequency and predefined internal address, if any. The
master transceiver may be located on or near the surface of a body
of water (such as on or coupled to a surface vessel or surface
buoy) or be in the body of water. In one embodiment, the acoustic
pinging device is connected to a highly accurate clock and
synchronized with it. The pinger may be actuated by automatic or
manual methods on the deck of a deployment vessel prior to
deployment. The pinger and/or its power supply may be configured to
be replaceable for each deployment, and in some embodiments, the
pinger is actuated by contact with water, thereby requiring the
pinger to be configured to be exposed to water. In some
embodiments, the acoustic pinging device might be actuated and
de-actuated remotely by one or more of any surface transceivers to
optimize its power consumption.
Monitoring and Positioning of Seismic Nodes
[0049] As discussed above, acoustic positioning transponders
attached to the deployed cable or rope have traditionally been used
to determine the positions of the cable/nodes during and after
deployment. These systems are very expensive and are often not used
as frequently as necessary for proper positioning of the
sensors/nodes. A need exists for an improved method and system for
the monitoring of cable deployed with nodes on the seabed, and in
particular one that eliminates all or substantially all of the
transponders typically used in such applications. In one
embodiment, each autonomous seismic node is coupled with an
acoustic pinging device whose signal may be detected by a
deployment vessel and/or a plurality of surface buoys that is towed
behind the deployment vessel. In another embodiment, a single
acoustic pinging device is coupled to every second, third, or
fourth node such that the system comprises less pingers than nodes.
The emitted pings allow the deployment vessel to monitor and/or
position the deployment of a plurality of autonomous seismic nodes
that are deployed from the vessel. This system is much more cost
effective than using transponders and allows better positioning and
accuracy of deployed nodes. Further, the pingers may also be used
to guide or position the cable and nodes as the deployment cable is
being deployed. Still further, the use of a plurality of surface
buoys connected to the deployment vessel eliminates the need for an
expensive and complex acoustic positioning system mounted on a pole
under a vessel (such as the commercially available system known as
Hi-PAP or any other USBL system) that is traditionally located on a
deployment vessel. Instead, a relatively simple acoustic
transceiver can be used on the deployment vessel and the surface
buoys to detect the emitted pings. Alternatively, while the
preferred embodiment utilizes inexpensive surface buoys to detect
the emitted pings, in other embodiments a plurality of autonomous
surface vehicles or other devices can travel or be towed behind the
deployment vessel and be used for monitoring and/or positioning of
the nodes and deployment cable. In other embodiments, an ocean
bottom cable with integrated pingers at selected locations can be
deployed from a deployment vessel and monitored in a similar manner
as described herein for autonomous nodes. In still other
embodiments, the disclosed system is configured to assess the
touchdown of a node and once it has achieved contact with the
seabed, ensure that the node is not moving.
[0050] FIG. 4 illustrates one system for using a single vessel to
monitor and/or position the deployment of seismic nodes on or near
the seabed. In one embodiment, deployment vessel 410 launches
deployment line 108 from water surface 401 with a plurality of
autonomous seismic nodes 430a, 430b attached to line 108. In one
embodiment, each seismic node 430 may be coupled to a pinger (such
as pinger 453) that is configured to emit a unique signal frequency
for that particular node. In other embodiments, a pinger may be
coupled to deployment line 108 between adjacent nodes, as is shown
by exemplary pinger 451 in FIG. 4. In still other embodiments, a
pinger may be placed between or coupled to every two, three, or
four nodes. During deployment, each pinger emits a ping at a
determined interval for a period of time. In one embodiment, the
pinger emits a ping every 5-10 seconds for a period of 10-20
minutes after deployment from the vessel, which for normal
operating conditions provides sufficient time for the node to reach
seabed 403. In other embodiments, as mentioned above, each pinger
may be configured to answer and/or otherwise respond to a request
from one or more surface transceivers. Such a two-way configuration
(interrogation by a surface transceiver and answer/response by a
pinger) may be preferred for short-range distances and/or for its
cost effectiveness as compared to a constantly emitting pinger
signal system.
[0051] In one embodiment, deployment vessel 410 is coupled to
acoustic receiver 414, which may be a transceiver. Acoustic
receiver 414 is configured to detect the emitted pings from a
plurality of nodes and/or associated pinging devices. A plurality
of surface buoys 420 (only one is shown for convenience in FIG. 4)
is coupled to deployment vessel 410 via one or more buoy connecting
lines 425 or through a wireless-communications link. Each surface
buoy 420 is coupled to an acoustic receiver 424 that is configured
to detect the emitted pings from a plurality of nodes. As is known
in the art based on any combination of communications principles
(such as triangulation techniques), the deployment vessel is
configured with appropriate computer systems to receive data from a
plurality of geographic locations (acoustic receiver 414 and
plurality of acoustic receivers 424) to calculate an accurate
subsea position of an emitted ping. Because a ping is associated
with a unique frequency for a specific node, the location of each
node can be determined. In other embodiments, each surface buoy
comprises a plurality of acoustic receivers. In one embodiment, the
plurality of acoustic receivers are placed at different depths in
the water, which provides greater accuracy on the calculated
positions of the nodes. For example, acoustic receiver/transceiver
414 may be placed on a pole a certain depth beneath deployment
vessel 410, which will be lower than any acoustic receivers 424
that are located on the water surface. In other embodiments, as
mentioned above, the communications system may be a two-way
communication system, in which case the surface buoys or vessels
use one or more transceivers instead of receivers. In this
configuration, one or more of the surface transceivers (such as one
coupled to a surface vessel) is configured to interrogate and/or
request a signal from one or more of the pingers. In response, the
pinger is configured to answer and/or otherwise respond to a
request from one or more surface transceivers. The answer from the
pinger/transducer may be received by a plurality of the surface
transceivers.
[0052] In one embodiment, surface buoy 420 may be towed behind
deployment vessel 410 and, in broadest terms, is any floating
device that can be towed behind a vessel on a surface of water and
coupled to a receiver and/or transceiver. For example, in one
embodiment, surface buoy comprises a buoy coupled to a metallic
frame, with an acoustic transducer mounted at the bottom of the
metallic frame, an acoustic transceiver mounted on top of the buoy,
and a GPS antenna mounted on the top of the mast. In one
embodiment, such a surface buoy may be any commercially available
tail buoy, such as an 800L or 1050L tail buoy from PartnerPlast AS,
or a custom made buoy. In one embodiment, surface buoy 420 may
include a control system and/or navigation system and communicate
with deployment vessel 410 via a cable and/or wireless
communications link. In other embodiments, a control system and/or
navigation system may be located on a deployment vessel 410 or
other surface vessel and communicate with one or more of the
plurality of surface buoys 420 via a cable and/or wireless
communications link. Surface buoy 420 may be configured with a
global positioning system (GPS) or other positioning system or
device that provides the buoy's exact position and time. Because a
GPS receiver on the surface buoy, by itself, may not provide
sufficient positioning coordinates for seismic applications, such a
GPS receiver may be processed in parallel with another GPS system
on the deployment vessel to have a range and bearing from the
vessel to the buoy. Thus, in one embodiment, a relative GPS (RGPS)
beacon is installed on surface buoy 420 and a reference antenna is
installed on the deployment vessel 410 or another surface vessel
(such as a seismic source vessel, which reduces calibration cost
and mobilization efforts for antennae synchronization). In other
embodiments, the GPS system on the buoy is an autonomous and
stand-alone differential GPS (DGPS) system and comprises a GPS
antenna and receiver on the mast of the surface buoy. DGPS is an
enhancement to basic GPS and provides improved location accuracy,
and receives differential correction signals based on/from a
network of ground-based reference stations that correct potential
inaccuracies in the basic GPS signal. In some situations, surface
buoy 420 may veer off its intended position based on surface waves,
vessel navigation or speed, etc., and thus surface buoy 420 may be
equipped with a propulsion system 422 (such as a propeller) that
maintains a desired position of the buoy and assists in proper
positioning of the buoy in reference to the deployment vessel 410
and other surface buoys. In some embodiments, surface buoy 420 may
be a self-positioning buoy that may be autonomous and
self-propelled and have GPS-positioning capabilities with a
navigation system. In other embodiments, surface buoy 420 may be
directed in real time by an operator or merely towed behind the
deployment vessel. In still other embodiments, surface buoy 420 may
comprise a combination of these navigation options, such that it is
towed behind the deployment vessel but also comprises a rudder or
other steering device to help retain the buoy in an optimum
position/offset from the subsea pingers.
[0053] Connecting line 425 may be a simple cable or wire, and
connecting line 425 may provide power, data, and/or both power and
data to and from plurality of surface buoys 420 and surface vessel
410. Each surface buoy needs a power source to provide power to any
communications (e.g., transceiver/receiver) equipment, GPS
equipment, and navigation/steering devices. Surface buoy may be
fully autonomous and have its own power supply. In one embodiment,
surface buoy 420 is equipped with batteries and/or local generating
power sources (such as solar panels on the top of the surface buoy
and/or water generators on the bottom of the surface buoy). In
another embodiment, the buoy's power is provided from a surface
vessel through a dedicated cable/umbilical (which may be the same
cable to tow the buoy if it is not self-propelled). In still
another embodiment, the power supply for the surface buoys may
comprise both power sources for redundancy and/or increased power
supply. Each surface buoy may also be configured to send (and
potentially receive) data to/from a surface vessel, and in other
embodiments, a surface buoy is configured to communicate with other
surface buoys. In one embodiment, the buoy is configured with a
cable telemetry device, such that data is provided to/from a
surface vessel through a dedicated cable/umbilical (which may be
the same cable to tow the buoy if it is not self-propelled). In
another embodiment, the buoy is configured with a wireless
telemetry device, such that data is provided to/from a surface
vessel through a dedicated radio-communications link. In one
embodiment, connecting line 425 is coupled to one surface buoy, but
in other embodiments (such as shown in FIGS. 6 and 7), multiple
surface buoys can be coupled to a single connecting line 425. While
the preferred embodiment utilizes inexpensive marine floating
devices (such as surface buoys) coupled to an acoustic receiver (or
transceiver) to detect the emitted pings, a plurality of autonomous
surface vehicles (USVs) can travel or be towed behind the
deployment vessel and be used for monitoring and/or positioning of
the nodes and deployment cable. In general, if a surface buoy is
self propelled, autonomous in power, and sends data to a surface
vessel via wireless means (such that the surface buoy is not
directly connected to a surface vessel via a dedicated cable or
line), the buoy may be considered to be a USV.
[0054] In one embodiment, system 400 is used to monitor and/or
position the deployment of plurality of autonomous seismic nodes
430. Based on the calculated positions of plurality of nodes 430,
the deployment vessel is able to track the deployment of nodes 430
and deployment line 108 in real-time or near real-time. With
real-time (or substantially/near real-time) information on the
location of the deployed nodes and deployment line, deployment
vessel 410 can vary the deployment route of deployment line 108 for
positioning of the nodes. Thus, the present disclosure provides a
much simpler and cost effective procedure for accurate positioning
of nodes on the seabed than previously possible. Further, the
present disclosure not only monitors the positions of the nodes but
also facilitates and/or guides the positioning of the nodes based
on calculated positions of the nodes. Still further, system 400 may
be configured to predict the touchdown position (i.e., the point of
contact of a node to the seabed) of the nodes being deployed based
on a calculation model with data supplied by the pingers. If the
predicted touchdown position for a node is too far away from where
a node (or a plurality of nodes) is supposed to be based on the
survey requirements and planned coordinates/pre-plot position, then
the deployment vessel can act on this estimated difference and vary
certain parameters (such as vessel position and speed) to minimize
the difference between the actual touchdown position and the
planned node positions. In one embodiment, such a guidance and/or
control system is located on vessel 410.
[0055] FIG. 5 illustrates a top view illustration of monitoring
system 500, which may be the same as or similar to system 400 from
FIG. 4. Deployment vessel 410 is configured with acoustic
receiver/transceiver 414 and tows a plurality of surface buoys 420
(such as first surface buoy 420a and second surface buoy 420b),
with each buoy 420 being coupled to deployment vessel 410 via a
buoy connecting line 425 (such as first connecting line 425a and
second connecting line 425b) or through a wireless-communications
link. As described in connection with FIG. 4, deployment vessel 410
and plurality of surface buoys 420 are each equipped with an
acoustic receiver/transceiver to detect the emitted signals from
the plurality of nodes 430. The further the plurality of surface
buoys 420 are positioned from each other and the deployment vessel
the more accurate the calculated position of the nodes. In one
embodiment, in order to optimize the accuracy of the position
calculated by this acoustic system, one or more receivers (or
transceivers) 420 are placed on both sides of cable 108 connected
to the plurality of nodes 430 (such as nodes 430a, 430b, etc.) and
associated subsea pingers. In one embodiment, plurality of surface
buoys 420 are positioned such that their respective positions
provide optimized positioning through triangulation and provide a
wide azimuth distribution of the acoustic ranges from and to the
subsea pingers.
[0056] FIG. 6 illustrates another system for using a single vessel
to monitor and/or position the deployment of nodes on or near the
seabed. System 600 is similar to the system described in FIGS. 4
and 5, but uses a plurality of surface buoys 420 and 422 coupled to
each connecting line 425 or through a wireless-communications link.
Thus, in one embodiment, first connecting line 425a is coupled to
first surface buoy 420a and second surface buoy 422a, while second
connecting line 425b is coupled to first surface buoy 420b and
second surface buoy 422b. The increased number of surface buoys
provides more available data as to the position of the emitted
pings, which allows a more accurate calculated position of the
nodes. In various embodiments, none, some, or all of the plurality
of surface buoys (e.g., buoys 420, 422) may be configured with a
propulsion system (not shown) to facilitate accurate positioning of
the surface buoys and/or to maintain a desired buoy position.
[0057] FIG. 7 illustrates another system for using a single vessel
to monitor and/or position the deployment of nodes on or near the
seabed. System 700 is similar to the system described in FIG. 6 but
uses only a single connecting line 425 (or through a
wireless-communications link) that is coupled to a plurality of
surface buoys 420 and 422. The use of single buoy connecting line
425 decreases potential line tangling between additional connecting
lines and deployment line 108.
[0058] FIG. 8 illustrates another system that is a combination of
FIG. 6 and FIG. 7. Rather than having multiple connecting lines
coming from the surface vessel (as is shown in FIG. 6), only one
cable 825a is coupled to surface vessel 410 in monitoring system
800. However, a plurality of cables/connecting lines 825b and 825c
are coupled to either cable 825a and/or surface buoy 820a such that
a plurality of additional surface buoys 820b and 820c are placed on
both sides of deployment cable 108 connected to the plurality of
nodes 430 and associated subsea pingers.
[0059] FIG. 9 illustrates one embodiment of a method for monitoring
and/or positioning of autonomous seismic nodes deployed on a
deployment line and/or cable. In an embodiment, the method 900
includes providing a plurality of surface buoys coupled to a
deployment vessel. The surface buoys can be coupled to the
deployment vessel via a single buoy connecting line or multiple
buoy connecting lines, and in other embodiments, no connecting line
is used and the surface buoys are coupled to the deployment vessel
wirelessly. Alternatively, USVs can be used instead of surface
buoys. The method further includes providing a plurality of
acoustic pinging devices coupled to a deployment line, as shown in
block 904. In one embodiment, an acoustic pinging device is coupled
to each autonomous seismic node. The pinger can be located within
the node's pressurized housing or external to the pressurized
housing, such as within a node bumper/fender. In other embodiments,
the pinger may be a stand-alone unit that is directly coupled to
the same deployment line as the seismic nodes such that one or more
pingers may be spaced on the deployment line between one or more of
the nodes. In other embodiments, only a subset of the plurality of
nodes comprises an acoustic pinger, such that every two, three, or
four nodes is coupled to or associated with an acoustic pinger. The
method further includes deploying the plurality of nodes from the
deployment vessel into a body of water, as shown in block 906. The
nodes are preferably attached to a deployment line or cable. The
method further comprises monitoring the deployment of the deployed
nodes by a plurality of surface buoys, as shown in block 908. In
one embodiment, each pinger on a node is configured to emit an
acoustic ping for a predetermined time after deployment, and the
plurality of surface buoys are configured to receive these pings.
In other embodiments, each pinger is configured to respond to a
request from a surface transceiver to transmit a ping, as discussed
in more detail herein. Each surface buoy may be configured with an
acoustic receiver, such as a hydrophone or similar device.
Likewise, the deployment vessel may also be configured with an
acoustic receiver. In other embodiments, the surface acoustic
devices may be transceivers that interrogate and/or request pings
from the subsea pinging devices. The method further comprises
calculating the position of the plurality of nodes based upon the
receipt and processing of the received pinger data from the
plurality of surface buoys, as shown in block 910. Pinger data
received from an acoustic receiver coupled to the deployment vessel
may also be used in the calculated position. The node positions can
be calculated after touchdown on the seabed as well as in route to
the seabed after deployment from a vessel.
[0060] The method further comprises, based on the calculated
positions of the nodes, positioning the route of the deployment
cable to optimize the survey pattern, as shown in block 912. In one
embodiment, the positioning step comprises guiding and/or
controlling the deployment of nodes and deployment cable based on
one or more predictions of a touchdown position of at least one
node. For example, if the predicted touchdown position for a node
is too far away from where a node is supposed to be based on the
survey requirements and planned coordinates, then the deployment
vessel can act on this estimated difference and vary certain
parameters (such as vessel position and speed) to minimize the
difference between the actual touchdown position and the planned
node positions. In other embodiments, the speed of the winch may be
varied which controls the slack/tension of the deployment line,
which affects the position of the deployment line and the positions
of the nodes and pingers. In still other embodiments, the disclosed
system is configured to assess the touchdown of a node and once it
has achieved contact with the seabed, ensure that the node is not
moving. For example, once the node achieves contact with the
seabed, the pinger coupled to the node (or, alternatively, a pinger
coupled to the deployment line on either side of the node)
continues to provide pings that are detected by the plurality of
service receivers/transceivers. If calculations based on these
pings show that the subsea pinging device is moving, this indicates
that the position of the node is moving and/or has moved. Of
course, one or more of these steps can be performed in various
orders or may not be necessary in all situations. For example,
providing surface buoys is not necessary prior to the deployment of
the nodes. In some embodiments, the nodes can be deployed first and
a short time thereafter the plurality of surface vessels are
deployed. Likewise, in some situations, the positions of the nodes
will just be calculated and monitored without any active guidance
of the deployed cable based on the calculated positions. Likewise,
instead of using a surface buoy, many other surface devices or
vessels can be utilized, such as USVs.
[0061] All of the methods disclosed herein can be made and executed
without undue experimentation in light of the present disclosure.
While the apparatus and methods of this invention have been
described in terms of preferred embodiments, it will be apparent to
those of skill in the art that variations may be applied to the
methods and in the steps or in the sequence of steps of the method
described herein without departing from the concept, spirit and
scope of the invention. In addition, modifications may be made to
the disclosed apparatus and components may be eliminated or
substituted for the components described herein where the same or
similar results would be achieved. All such similar substitutes and
modifications apparent to those skilled in the art are deemed to be
within the spirit, scope, and concept of the invention.
[0062] Many other variations in the configurations of the node,
acoustic pingers, and surface buoys are within the scope of the
invention. For example, the node may or may not be directly
attached to the deployment cable, and in some instances may merely
be tethered to the deployment cable. The acoustic pingers may be
directly attached to one or more of the nodes or may be merely
coupled to the deployment cable in selected positions proximate to
the nodes. In such a situation, the pingers may be selectively
attached to the deployment cable based on the particular survey and
other constraints. While a surface buoy is the embodiment discussed
most in this disclosure, other surface devices that comprise a
receiver or transceiver may be used, such as unnamed surface
vessels (USVs). As another example, while embodiments described
herein often times illustrate a physical cable connecting the
surface buoys to the surface vessel, no such cable may be needed if
the surface buoys or USVs are self-positioning and if any data
communications to the surface vessel are done wirelessly.
Similarly, a buoy connecting line may actually be composed of
multiple wire segments, with each of the segments being connected
to one or more surface buoys. Further, the disclosure is applicable
for autonomous seismic nodes attached to a deployment cable or
ocean bottom cable integrated with seismic nodes. It is emphasized
that the foregoing embodiments are only examples of the very many
different structural and material configurations that are possible
within the scope of the present invention.
[0063] Although the invention(s) is/are described herein with
reference to specific embodiments, various modifications and
changes can be made without departing from the scope of the present
invention(s), as presently set forth in the claims below.
Accordingly, the specification and figures are to be regarded in an
illustrative rather than a restrictive sense, and all such
modifications are intended to be included within the scope of the
present invention(s). Any benefits, advantages, or solutions to
problems that are described herein with regard to specific
embodiments are not intended to be construed as a critical,
required, or essential feature or element of any or all the
claims.
[0064] Unless stated otherwise, terms such as "first" and "second"
are used to arbitrarily distinguish between the elements such terms
describe. Thus, these terms are not necessarily intended to
indicate temporal or other prioritization of such elements. The
terms "coupled" or "operably coupled" are defined as connected,
although not necessarily directly, and not necessarily
mechanically. The terms "a" and "an" are defined as one or more
unless stated otherwise. The terms "comprise" (and any form of
comprise, such as "comprises" and "comprising"), "have" (and any
form of have, such as "has" and "having"), "include" (and any form
of include, such as "includes" and "including") and "contain" (and
any form of contain, such as "contains" and "containing") are
open-ended linking verbs. As a result, a system, device, or
apparatus that "comprises," "has," "includes" or "contains" one or
more elements possesses those one or more elements but is not
limited to possessing only those one or more elements. Similarly, a
method or process that "comprises," "has," "includes" or "contains"
one or more operations possesses those one or more operations but
is not limited to possessing only those one or more operations.
* * * * *